Buick LaCrosse III (2016-2019) (lower left end of dash) Wiring diagrams

ACC IGN VOLT ACC IND ADAPTIVE CRUISE CTRL GAP UP/DOWN SW SIG AMBIENT LIGHT SENS SIG ANTI-LOCK BRAKES SYSTEM ANTI-LOCK BRAKES, CRUISE CONTROL, EXTERIOR LIGHTS SYSTEMS ANTI-THEFT SYSTEM BATTERY POSITIVE VOLT BLK WIRE BLK/BRN WIRE BLK/GRY WIRE BLK/YEL WIRE BLU WIRE BLU/BLK WIRE BLU/GRN WIRE BRAKE APPLY SENS CTRL BRAKE APPLY SENS LOW REF BRAKE APPLY SENS SIG BRN WIRE BRN/BLK WIRE CHARGE IND CTRL COMPUTER DATA LINES SYSTEM CRUISE CONTROL SYSTEM DIMMER SW LO REF DIMMER SW SIG DIMMIMG IND DK BLU WIRE DK BLU/GRY WIRE DK BLU/RED WIRE DK BLU/YEL WIRE DK GRN WIRE DK GRN/BLK WIRE DK GRN/GRY WIRE DK GRN/VIO WIRE DK GRN/WHT WIRE DOOR LOCKS, ANTI-THEFT SYSTEMS ENGINE START/ STOP EXTERIOR LIGHTS, INTERIOR LIGHTS SYSTEMS FRT FOG LP SW SIG CTRL FUSE 18 FUSE 20 FUSE 21 FUSE 22 FUSE 29 FUSE 5 FUSE 8 GRN WIRE GROUND GRY WIRE GRY/VIO WIRE GRY/WHT WIRE HAZARD LED DIMMING SIGNAL HAZARD SW LEFT TURN SIG HAZARD SW RIGHT TURN SIG HAZARD SW SIG HDLP DIMMER SW HI BEAM SIG HDLP SW FLASH TO PASS SIG HORN SW SIG HDLP SW HDLP OFF SIG CTRL HDLP SW ON SIG HDLP SW PARK LAMPS SIG HEADLIGHTS SYSTEM HI SPD GMLAN SERIAL DATA (+) 1 REMOTE FUNCTION ACTR CTRL HI SPD GMLAN SERIAL DATA (+) 1 REMOTE FUNCTION ACTUATOR RECEIVE SIG HI SPD GMLAN SERIAL DATA (-) (1) HORNS SYSTEM HOT AT ALL TIMES IGN MODE SW ACC LED SIG IGN MODE SW START LED SIG IGNITION MODE SW MODE VOLT IGNITION MODE SWITCH INDICATOR DIMMING CTRL INSTRUMENT PANEL FUSE BLOCK KEYLESS ENTRY CONTROL MODULE LED BACKLIGHT DIMMING CTRL LIN BUS 15 LINEAR INTERCONNECT NETWORK SERIAL DATA BUS 4 LOW SPD GMLAN SERIAL DATA LT GRN WIRE PASSIVE START SW 2 LOW REF PASSIVE START SW SIG 2 POWER DISTRIBUTION SYSTEM RAP RLY COIL CTRL RED WIRE RED/BLU WIRE RED/BRN WIRE RED/DK GRN WIRE RED/GRY WIRE RED/WHT WIRE RED/YEL WIRE REMOTE FUNCTION ACTR TRANSMIT SIGNAL RUN/CRANK IGN 1 VOLT SECURITY INDICATOR CTRL SET/COAST/RESUME/ ACCELERATE SW SIG WINDSHIELD WIPER SW LOW REF START IND TRACTION CTRL SW SIG 1 TRANSMISSIONS SYSTEM UP/TAP DOWN SW SIG VIO WIRE VIO/BLK WIRE VIO/YEL WIRE WHT WIRE WINDSHIELD WASHER SW SIG WINDSHIELD WIPER SW HI SIG WINDSHIELD WIPER SW LOW SIG WIPER/WASHER SYSTEM YEL WIRE YEL/GRY WIRE

A/C PRESS SENS A/C REFRIGERANT PRESS SENS SIG A/C REFRIGERANT PRESSURE SENSOR AIR TEMP SENS SIG AMBIENT AIR TEMPERATURE SENSOR BATT POS VOLT BATT POS VOLT COOLING FAN CTRL RELAY SPEED SIG BLK WIRE BLK/BLU WIRE BLK/BRN WIRE BLK/WHT WIRE BLU WIRE BLU/GRY WIRE BRN/RED WIRE COMPUTER DATA LINES SYSTEM COOL FAN FUSE DK BLU WIRE DK GRN WIRE DRIVER INFORMATION CENTER DISPLAY EBOOST/ COOL FAN LT FUSE ENG COOLANT TEMP SENS SIG ENGINE CONTROL MODULE (LEFT FRONT OF ENGINE COMPT) ENGINE COOLANT TEMPERATURE GAUGE ENGINE COOLANT TEMPERATURE IND ENGINE COOLANT TEMPERATURE SENSOR FUSE 9 GROUND GRY/LT GRN WIRE HI SPEED GMLAN SERIAL DATA (-) 1 HOT AT ALL TIMES INSTRUMENT CLUSTER INSTRUMENT PANEL FUSE BLOCK LEFT COOLING FAN MOTOR (BEHIND LEFT SIDE OF RADIATOR) LOGIC LOW SPEED GMLAN SERIAL DATA 2 NCA WIRE RED/BRN WIRE RED/YEL WIRE RELAY SPEED SIG RIGHT COOLING FAN MOTOR (BEHIND RIGHT SIDE OF RADIATOR) SENS LOW REF SIG GROUND UNDERHOOD FUSE BLOCK WHT WIRE WHT/BLK WIRE

73 8 SIG GND ADAPTIVE CRUISE IND APP LO REF (1) APP LOW REF 2 APP SIG (1) APP SIG (2) BATT POSITIVE VOLT BLK WIRE BLK/BRN WIRE BLK/DK BLU WIRE BLK/RED WIRE BLK/VIO WIRE BLK/WHT WIRE BLK/YEL WIRE BODY CONTROL MODULE (UNDER FLOOR CONSOLE) BRAKE APPLY SENS CTRL BRAKE APPLY SENS LOW REF BRAKE APPLY SENS SIG BRAKE PEDAL POSITION SENSOR (TOP OF BRAKE PEDAL ASSEMBLY) BRAKE POS SENS LOW REF BRAKE POS SENS SIG BRN WIRE BRN/RED WIRE BRN/WHT WIRE COMPUTER DATA LINES SYSTEM CRUISE IND CRUISE/ETC/TCC BRK SIG DATA 2 (+) DK BLU WIRE DK BLU/WHT WIRE DK BLU/YEL WIRE DK GRN/WHT WIRE DRIVER INFORMATION CENTER DISPLAY ECM IGN FUSE ENGINE CONTROL MODULE (LEFT FRONT OF ENGINE COMPT) FUSE 20 FUSE 5 GMLAN GRY WIRE GRY/LT GRN WIRE HIGH SPD GMLAN SERIAL DATA (+) 1 HOT AT ALL TIMES HOT W/ IGNITION MAIN RELAY ENERGIZED INSTRUMENT CLUSTER INSTRUMENT PANEL FUSE BLOCK LOGIC LOW SPD LT GRN/WHT WIRE MAIN RELAY FUSED SUPPLY 2 RED WIRE RED/BRN WIRE RED/WHT WIRE RED/YEL WIRE RUN/CRANK IGN 1 VOLT SERIAL SERIAL DATA (-) (1) SET/COAST/RESUME/ ACCELERATE SW THROTTLE ACTUATOR CTRL CLOSE THROTTLE ACTUATOR CTRL OPEN THROTTLE POS SENS LOW REF THROTTLE POS SENS SIG UNDERHOOD FUSE BLOCK UP/DOWN SW SIG VIO/LT GRN WIRE WHT WIRE WHT/BLU WIRE WHT/LT GRN WIRE WHT/RED WIRE YEL WIRE YEL/WHT WIRE

5 VOLT REF BLK WIRE BLK/BRN WIRE BLK/YEL WIRE BLU/WHT WIRE BRAKE PEDAL POSITION SENSOR BRK POS SENS BRK POS SENS SIG BRN/DK GRN WIRE BRN/YEL WIRE COMPUTER DATA LINES SYSTEM DK BLU WIRE DK BLU/YEL WIRE ENGINE CONTROL MODULE FUSE 20 GRN/VIO WIRE GRN/YEL WIRE GROUND DISTRIBUTION SYSTEM GRY/BRN WIRE GRY/GRN WIRE HI SPEED GMLAN HOT AT ALL TIMES INSTRUMENT PANEL FUSE BLOCK LO REF NCA WIRE RED/BRN WIRE RIGHT AUXILIARY TAIL LAMP RIGHT CORNERING LAMP RIGHT FRONT SIDE MARKER LAMP RIGHT FRONT TURN SIGNAL LAMP RIGHT HEADLAMP ASSEMBLY RIGHT PARK DAYTIME RUNNING LAMP RIGHT REAR COMPARTMENT LID TAIL LAMP ASSEMBLY SERIAL DATA (-) (1) VIO/GRN WIRE VIO/WHT WIRE W/ HID W/O HID WHT WIRE WHT/GRN WIRE WHT/LT GRN WIRE WHT/RED WIRE WHT/YEL WIRE YEL/WHT WIRE

ACTR CTRL ACTR RECEIVE ACTR TRANSMIT AMBIENT LIGHT/SUNLOAD SENSOR BATT POSITIVE VOLT BLK WIRE BLU WIRE BODY CONTROL MODULE (UNDER FLOOR CONSOLE) BRN WIRE BRN/GRN WIRE BRN/VIO WIRE BRN/WHT WIRE BRN/YEL WIRE COMPUTER DATA LINES SYSTEM DK BLU WIRE DK BLU/BLK WIRE DR LCK ACTUATOR LCK CTRL DR LCK ACTUATOR LCK CTRL 2 DR LCK ACTUATOR UNLCK CTRL DRIVER DOOR LOCK SWITCH DRV DR LCK SW LCK SIG DRV DR LCK SW UNLCK SIG FRONT, REAR PARK ASSIST, LANE KEEP ASSIST FUSE 20 FUSE 41 GRY WIRE GRY/WHT WIRE HAZARD SW SIG HEADLAMP HI BEAM RLY CTRL HEADLIGHTS SYSTEM HOOD STATUS B SIG HORN RLY CTRL HORNS SYSTEM HOT AT ALL TIMES IND DIMMING CTRL INSTRUMENT PANEL FUSE BLOCK INTERIOR LIFTGATE AJAR SW SIG 1 LIGHTS SYSTEM LR DR LCK MTR STATUS LT GRN WIRE PASS DR LCK SW LCK CTRL PASS DR LCK SW UNLCK CTRL PASSENGER DOOR LOCK SWITCH POWER SUPPLY TRANSFORMER REAR COMPARTMENT LID LATCH RED/BRN WIRE RED/YEL WIRE REMOTE CONTROL DOOR LOCK RECEIVER REMOTE FUNCTION ACTR CTRL REMOTE FUNCTION ACTR RECEIVE SIG REMOTE FUNCTION ACTR TRANSMIT SIG RR DR LCK MTR STATUS SECURITY IND CTRL SERIAL DATA (+) (3) SERIAL DATA (-) (1) SIG SPLY VOLT 1 VIO WIRE VIO/GRY WIRE W/ START/STOP SYSTEM W/ START/STOP SYSTEM W/O START/STOP SYSTEM WHT WIRE WHT/VIO WIRE YEL WIRE YEL/DK BLU WIRE YEL/DK GRN WIRE YEL/VIO WIRE

ACC IGN VOLT ACTIVE SIG ACTR CTRL ACTR RECEIVE ACTR TRANSMIT AMBIENT LIGHT/SUNLOAD SENSOR BATT POSITIVE VOLT BLK WIRE BLU WIRE BODY CONTROL MODULE (UNDER FLOOR CONSOLE) BRN WIRE BRN/GRN WIRE BRN/VIO WIRE BRN/WHT WIRE BRN/YEL WIRE COMPUTER DATA LINES SYSTEM DATA BUS 3 DK BLU WIRE DK GRN/YEL WIRE DR LCK ACTUATOR LCK CTRL DR LCK ACTUATOR LCK CTRL 2 DR LCK ACTUATOR UNLCK CTRL DRIVER DOOR LOCK SWITCH DRV DR LCK SW LCK SIG DRV DR LCK SW UNLCK SIG ENGINE CONTROL MODULE FUSE 20 FUSE 41 GRY WIRE GRY/WHT WIRE HAZARD SW SIG HEADLAMP HI BEAM RLY CTRL HEADLIGHTS SYSTEM HOOD AJAR SWITCH HOOD STATUS A SIG HOOD STATUS B SIG HORN RLY CTRL HORNS SYSTEM HOT AT ALL TIMES IND DIMMING CTRL INSTRUMENT PANEL FUSE BLOCK INTERIOR LIFTGATE AJAR SW SIG 1 LIGHTS SYSTEM LOGIC LR DR LCK MTR STATUS LT GRN WIRE PASS DR LCK SW LCK CTRL PASS DR LCK SW UNLCK CTRL PASSENGER DOOR LOCK SWITCH PASSENGER WINDOW MOTOR PPL REAR COMPARTMENT LID LATCH RED/BRN WIRE RED/YEL WIRE REMOTE CONTROL DOOR LOCK RECEIVER REMOTE FUNCTION ACTR CTRL REMOTE FUNCTION ACTR RECEIVE SIG REMOTE FUNCTION ACTR TRANSMIT SIG GND RF DR AJAR RR DR LCK MTR STATUS RUN/CRANK IGN 1 VOLT SECURITY IND CTRL SERIAL DATA (-) (1) SIG SW SIG VIO WIRE VIO/BLK WIRE VIO/GRY WIRE VIO/YEL WIRE WHT WIRE WHT/VIO WIRE YEL WIRE YEL/DK BLU WIRE YEL/DK GRN WIRE YEL/VIO WIRE

A/C COMPRESSOR CLUTCH AIR IONIZER AUTOMATIC TRANSMISSION ASSEMBLY TRANSMISSION CONTROL MODULE BATTERY SAVER RELAY 1 BLK WIRE BLK/WHT WIRE BRN WIRE CENTER CONSOLE COMPARTMENT LAMP CENTER CONSOLE FLOOD LAMP DATA LINK CONNECTOR ENGINE CONTROL MODULE ENGINE OIL LEVEL SWITCH GRN/BLU WIRE HAZARD WARNING SWITCH HORN SWITCH INFLATABLE RESTRAINT SENSING, DIAGNOSTIC MODULE INSTRUMENT PANEL COMPARTMENT LAMP INSTRUMENT PANEL FUSE BLOCK INSTRUMENT PANEL MULTI- FUNCTION SWITCH LEFT INSTRUMENT PANEL ACCENT LAMP LEFT INSTRUMENT PANEL COURTESY LAMP LEFT STEERING WHEEL CONTROLS SWITCH LEFT TRANSMISSION MANUAL SHIFT SWITCH MIDDLE INSTRUMENT PANEL ACCENT LAMP MULTI-FUNCTION INTAKE AIR SENSOR NCA WIRE PARK BRAKE CONTROL SWITCH PASSENGER PRESENCE MODULE RED WIRE RED/BLK WIRE RETAINED ACCESSORY POWER RELAY RIGHT INSTRUMENT PANEL ACCENT LAMP RIGHT INSTRUMENT PANEL COURTESY LAMP RIGHT STEERING WHEEL CONTROLS SWITCH RIGHT TRANSMISSION MANUAL SHIFT SWITCH STARTER RELAY STEERING COLUMN POSITION CONTROL MODULE STEERING WHEEL AIR BAG COIL STEERING WHEEL HEATER STEERING WHEEL HEATING CONTROL MODULE TRANSMISSION RANGE CONTROL MODULE UNDERHOOD FUSE BLOCK

ACTR CTRL ACTR RECEIVE ACTR TRANSMIT AMBIENT LIGHT/SUNLOAD SENSOR BATT POSITIVE VOLT BLK WIRE BLU WIRE BODY CONTROL MODULE (UNDER FLOOR CONSOLE) BRN WIRE BRN/GRN WIRE BRN/VIO WIRE BRN/WHT WIRE BRN/YEL WIRE COMPUTER DATA LINES SYSTEM DK BLU WIRE DK BLU/BLK WIRE DR LCK ACTUATOR LCK CTRL DR LCK ACTUATOR LCK CTRL 2 DR LCK ACTUATOR UNLCK CTRL DRIVER DOOR LOCK SWITCH DRV DR LCK SW LCK SIG DRV DR LCK SW UNLCK SIG FRONT, REAR PARK ASSIST, LANE KEEP ASSIST FUSE 20 FUSE 41 GRY WIRE GRY/WHT WIRE HAZARD SW SIG HEADLAMP HI BEAM RLY CTRL HEADLIGHTS SYSTEM HOOD STATUS B SIG HORN RLY CTRL HORNS SYSTEM HOT AT ALL TIMES IND DIMMING CTRL INSTRUMENT PANEL FUSE BLOCK INTERIOR LIFTGATE AJAR SW SIG 1 LIGHTS SYSTEM LR DR LCK MTR STATUS LT GRN WIRE PASS DR LCK SW LCK CTRL PASS DR LCK SW UNLCK CTRL PASSENGER DOOR LOCK SWITCH POWER SUPPLY TRANSFORMER REAR COMPARTMENT LID LATCH RED/BRN WIRE RED/YEL WIRE REMOTE CONTROL DOOR LOCK RECEIVER REMOTE FUNCTION ACTR CTRL REMOTE FUNCTION ACTR RECEIVE SIG REMOTE FUNCTION ACTR TRANSMIT SIG RR DR LCK MTR STATUS SECURITY IND CTRL SERIAL DATA (+) (3) SERIAL DATA (-) (1) SIG SPLY VOLT 1 VIO WIRE VIO/GRY WIRE W/ START/STOP SYSTEM W/ START/STOP SYSTEM W/O START/STOP SYSTEM WHT WIRE WHT/VIO WIRE YEL WIRE YEL/DK BLU WIRE YEL/DK GRN WIRE YEL/VIO WIRE

ACC IGN VOLT ACTIVE SIG ACTR CTRL ACTR RECEIVE ACTR TRANSMIT AMBIENT LIGHT/SUNLOAD SENSOR BATT POSITIVE VOLT BLK WIRE BLU WIRE BODY CONTROL MODULE (UNDER FLOOR CONSOLE) BRN WIRE BRN/GRN WIRE BRN/VIO WIRE BRN/WHT WIRE BRN/YEL WIRE COMPUTER DATA LINES SYSTEM DATA BUS 3 DK BLU WIRE DK GRN/YEL WIRE DR LCK ACTUATOR LCK CTRL DR LCK ACTUATOR LCK CTRL 2 DR LCK ACTUATOR UNLCK CTRL DRIVER DOOR LOCK SWITCH DRV DR LCK SW LCK SIG DRV DR LCK SW UNLCK SIG ENGINE CONTROL MODULE FUSE 20 FUSE 41 GRY WIRE GRY/WHT WIRE HAZARD SW SIG HEADLAMP HI BEAM RLY CTRL HEADLIGHTS SYSTEM HOOD AJAR SWITCH HOOD STATUS A SIG HOOD STATUS B SIG HORN RLY CTRL HORNS SYSTEM HOT AT ALL TIMES IND DIMMING CTRL INSTRUMENT PANEL FUSE BLOCK INTERIOR LIFTGATE AJAR SW SIG 1 LIGHTS SYSTEM LOGIC LR DR LCK MTR STATUS LT GRN WIRE PASS DR LCK SW LCK CTRL PASS DR LCK SW UNLCK CTRL PASSENGER DOOR LOCK SWITCH PASSENGER WINDOW MOTOR PPL REAR COMPARTMENT LID LATCH RED/BRN WIRE RED/YEL WIRE REMOTE CONTROL DOOR LOCK RECEIVER REMOTE FUNCTION ACTR CTRL REMOTE FUNCTION ACTR RECEIVE SIG REMOTE FUNCTION ACTR TRANSMIT SIG GND RF DR AJAR RR DR LCK MTR STATUS RUN/CRANK IGN 1 VOLT SECURITY IND CTRL SERIAL DATA (-) (1) SIG SW SIG VIO WIRE VIO/BLK WIRE VIO/GRY WIRE VIO/YEL WIRE WHT WIRE WHT/VIO WIRE YEL WIRE YEL/DK BLU WIRE YEL/DK GRN WIRE YEL/VIO WIRE

BATT POS VOLT BLK WIRE BODY CONTROL MODULE (UNDER FRONT CONSOLE) BRN/GRY WIRE COMPUTER DATA LINES SYSTEM DC DC BATT 2/AWD FUSE DELAY SWITCH DK BLU WIRE DK GRN/BRN WIRE DRIVER INFORMATION CENTER DISPLAY FRT WPR FUSE FUSE 20 FUSE 41 GRY WIRE GRY/LT GRN WIRE GRY/VIO WIRE HI SPD GMLAN SERIAL DATA (-) (1) HOT AT ALL TIMES INSTRUMENT CLUSTER INSTRUMENT PANEL FUSE BLOCK LIN SERIAL DATA BUS 1 LOGIC LOW SPD GMLAN SERIAL DATA 2 OFF MIST POWER SUPPLY TRANSFORMER RED/BRN WIRE RED/DK BLU WIRE RED/YEL WIRE SPLY VOLT 1 UNDERHOOD FUSE BLOCK W/O START/STOP SYSTEM W/ START/STOP SYSTEM WASH PUMP FUSE WASHER SWITCH WHT WIRE WINDSHIELD WASHER PUMP WINDSHIELD WASHER PUMP RELAY WINDSHIELD WASHER RLY CTRL WINDSHIELD WASHER SW SIG WINDSHIELD WIPER MOTOR WINDSHIELD WIPER MTR RLY COIL CTRL WINDSHIELD WIPER SW HI SIG WINDSHIELD WIPER SW LO REF WINDSHIELD WIPER SW LOW SIG WINDSHIELD WIPER/WASHER SWITCH WIPER SWITCH YEL WIRE